Circuit-controlling system.



J. H. HALL. 01mm CONTROLLING SYSTEM. APPLICATION FILED NOV. 28, 1910.1,053,494 r Patented Feb. 18, 1913.

4 SHEETSSHEET 1.-

INVENTOI ga 4M J. H. HALL.-

CIRCUIT CONTROLLING SYSTEM.

APPLIOATION'PILED NOV. 28, 1910.

1 ,05 3 ,4-94, Patented Feb. 18, 1913@ 4 SHEETSSHEET Z.

FIG. 2

WITH ESSES NW EN'FOR J. H. HALL.

CIRCUIT CONTROLLING SYSTEM.

AYPLIOATION FILED NOV. 28, 1910.

1,053,494. Patented Feb; 18, 1913.

I 4 SHEETS-SHEET 3- FIG. 3

WITNESSES mm I 9'40 07 W J. H. HALL.

CIRCUIT CONTROLLING SYSTEM.

APPLIOATION I'ILED'NOV. 2's, 1910.

1 053 494 Patented Feb. 18, 1913.

4 S EEETSSHEE'I: 4.

FIG. 4

WITNESSES STATES rn'rENT OFFICE.

JAY H. HALL, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELECTRIC CONTROLLER ANDMANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

I CIBOUIT-CONTBOLLING SYSTEM.

Specification of Letters Patent.

Patented Feb..18,1913.

Application fled November 28, 1810. Serial No. 594,440. p v

To all whom it may concern Be it known that I, JAY H. HELL, a citizen ofthe United States, residing at Cleveland, in the county of Cuyahoga andState of Ohio, have invented new and usefui Improvements inGircuit-Controllin Systems, of which thefollowing is a speci cat1on-.

My invention relates to circuit controlling systems and particularly tothe control of electric motors in which it is desired to protect themotor from being restartedwithout the attention of an operator upon anover-- load or failure of voltage, and to protect the motor-from beingstarted with any of' age without" further attention from an operator,and'which cannot be closed if any of the starting resistance is cut out.

Referring to the accompanying drawings, Figures 1, 2, and 3 are diagramsillustrating three of the many species which my invention may assume.Fig. 4 is a vertical section, partly in side elevation showing themagnetically-operated switch hereinbefore mentioned. Fig. 5 is a frontelevation of Fig. 4.

The switch S shown on Figs. 4 and 5 is the same as that shown anddescribed in my application, Serial Number 583,747, except that theupper boss or core is provided with two windings instead of one. Thisswitch is briefly described as follows: The frame S of magnetic materialis secured to the base S of insulating material and has the upperpendent boss or core S surrounded by' the two independent windings S andS. The frame is also provided with the adjustable lower boss or core Ssurrounded by the winding S. S is the plunger or armature movablebetween the cores under the" control oi thesaid windings as will bepresently explained. The plunger is connected by the preferablynon-magnetic rod.

brush- S mounted on the base S S" to the switch arm S pivoted totheframe on the pin S and arranged to enga e the is a sleeve ofnon-magnetic material surroundmg the preferablymagnetic reduced exten-.sion S 01- the plunger S. The core S is threaded in the frame so thatthe length of the lower air-gap S may be adjusted. S represents theupper air-gap which is-between the core S and the plunger. S and S arethe terminals of the winding S".

S is a shoulder to limit the descent of the plunger S". If either of thewindings S or S is energized with a small amount of excitation, theswitch arm S cannot be operated by the winding S, but if after theswitch is once operated by the winding S" and the gap S is closed, asmall amount of excitation of the winding S or S will not cause theswitch to 'open; but a very large amount of excitation of either ofthese windings, or both together, will cause the winding- S to pull theplunger S down, thereby opening the switch S. To obtain this action themagnetic flux set up by the windings S and S should be ina directionopposite to the flux set up by the windving'S. a

Fig. 1 shows conventionally the switch S used in connection with amanually operated starting rheostat' or controller C to control themotor having'the armature-A and the shunt field f. I have shown theshunt field f connected directly across the source of supply as soon asthe switch M is ,closed' When the arm of the controller is imoved to thefirst running position, the :brush C connects the segments C and (l anda circuit is established through the op- Ierating winding S of theswitch S from the positive to the contact C, the brush C .the contact(1, the wire 1, and the winding- S to the negative main. This circuitcauses .the switch S to close its contacts and establish a motor circuitthrough the armature A including all of the starting resistance R andthe winding S The motor now starts at its slowest speed. As thecontroller handle is moved to the right, the starting resistance R isgradually cut out, and in the final. right-hand position the motorarmature is connected directly across theline.

As soon as the controller handle is moved to the second contact,thebrush G connects the contact segment 0* to the segment C, therebyestablishing a circuit through the winding 8 and the adjustableresistance 7*. During the running of the motor the windings S and S areboth energized, but the switch S may be so adjusted by the core S andthese windings so proportioned that for all safe values of currentthrough the armature the switch will remain in its closed position. If,however, an overload occurs, the current in the winding S increases andcauses the switch S to open, thereby disconnecting the motor from thesource of supply. The handle of the controller C still remaining in theposition at which the overload occurred, both of the windings S and Sremain energized. This energization of the winding S prevents the switchfrom closing until the handle is moved back to the first runningposition, or until the brush C has left the contact C, at which positionthe winding S becomes detinergized, and allows the winding S to againclose the switch and restart the motor. If, while the handle of thecontroller C is left in a running position, there should be a failure ofvoltage, all of the windings become deenergized, causing the'switch S toopen and disconnect the motor from the source of supply. Upon a returnof voltage the windings S and S will be energized simultaneously,thereby preventing the switch from closing and it will be necessary forthe operator to move the handle back to the first running position inorder to restart the motor. It is, therefore. seen that it is impossibleto close the switch S to start the motor with any of the startingresistance cutout.

To stop the motor, the switch M may be opened or the controller handlemay be moved to the ott-position.

The switch may be adjusted to operate on different overload currentseither by the adustment of the magnetic circuit by means of the boss S,or by the adjustment of the resistance 1- In Fig. 2, I have shown theswitch S used in connectlon with a series of magnetic switches forautomatically cutting out the starting resistances RQR R by means of themagnetic switches S S", S of the type described in Canfieidsapplications, Serial Number 583.000, filed September 21, 1910, andSerial Number 604,33Lfiled January 23. 19l1, and in Eastwoods patent,No. 1,040,292, granted October 8, 1912. In these applications and inthis patent, particularly in Fig. 2, the switches have the peculiarcharacteristic that they remain in their open position when theiroperating windings are energized above a predetermined value, andoperate to close their contacts when the energization falls to thisvalue. As soon as the switch M is closed, the shunt field f isimmediately energized, and a circuit is also establishedfrom thepositive through the windings S and S to the negative. As beforeexplained, the simultaneous excitation of these two windings preventsthe switch S from closing.

When it is desired to start the motor the operator presses the pushbutton P. which short-circuits the winding S allowing the winding S toclose the switch. A motor circuit is now established from the positivethrough the winding S, the contacts of the switch S, the operatingwinding S of the switch S the starting resistances R, R and R and themotor armature A to the negative. The motor starts with all theresistance in series, and operates at its slowest speed. When the motorarmature has speeded up and the current therein is diminished to acertain predetermined value, the winding S closes the switch S, therebyshort-circuiting the resistance R and connecting the operating winding Sof the switch S in the motor circuit. Similarly the switches S and Sclose successively when the armature current has diminished to apredetermined value, thereby automatically bringing the motor up tospeed and finally connecting the armature directly across the line. Itnow an overload occurs, the winding S in the switch S will cause thisswitch to open, and since the windings S and S are still connectedacross the source of supply, the switch S will be prevented from closingagain until the operator again closes the push button switch P.Similarly, on the i occasion of failure of voltage while the motor isrunning, all of the switch windings will be denergized, the switch Swill open, and upon the return of voltage the windings S and S will beenergized simultaneously, thereby preventing the switch S from closinguntil the operator has again closed the push button switch P.

To stop the motor the switch M or the small switch at may be opened.

In Fig. 2 I have shown another means of adjusting the point at which theoverload current will cause the switch S to be opened, which consists inusing an adjustable resistance shunt K, which may be connected acrossthe terminals of the winding On the upper boss of the switch S I haveshown a winding S' which is connected in the motor circuit when theswitch S closes its contacts. This winding may be so proportioned. andthe magnetic circuit of the switch so adjusted that for all ordinaryvalues of the motor current the switch S will remain closed, but. uponthe occasion of an increased current throngh the motor which would notbe large enough to cause the main switch S to open, but which would betoo large for a safe runningvalue, the

- the push button switch P, thereby inserting predetermined value.

winding S will cause the switch S to open and insert all the startingresistance in series with the motor armature. This switch then becomes atorque limit device which will insert a certain amount of the startingresistance in series with the motor upon an increase of current-above acertain It the overload is removed, the switcheswill again closeautomatically, cut out the starting resistance, and bring the motor upto speed.

I am aware that a torque limit in itself is not new, but this method ofobtaining it without the use of a separate switch or relay is believedto be entirely new.

Fig. 3 shows a system of inotor control in which the main switch SA hasonly the two windings S and S As soon as this system is connected to asource of supply by the closing of the switch M, the shunt field fbecomes energized, and a circuit is established from the positivethrough the winding S, the switch at and the contacts of the switch P tothe negative. The winding S when energized without operating the pushbutton switch P, is designed to cause.

the switch SA to be locked open by the action of too large a current forclosing it; In order to close the switch SA to'start the motor theoperator must open the contacts of the resistance 1"" in the circuit.This resistance reduces the current in the winding S to a value at whichit will operate the switch SA, which upon operation closes the motorcircuit, including the winding S. The resistance switches S S and S ofany type,

V such as shown in Fig. 2, may now be closed, short-circuiting theresistance R and bringing the motor up to speed. As soon as the operatorremoves his hand from the switch P, the spring 127 closes its contactsagain, in creasing the current through the winding S so that, upon anoverload in the winding S, which causes the switch SA to open and cutofi the motor from the line, the winding S will be fully energized andlock the switch SA open until the operator again actuates the pushbutton switch P to restart the motor. The same action occurs upon theoccasion of no-voltage, at which the switch SA opens. Upon the return ofvolt age, the winding S will be fully energized and lock the switch openuntil the operator actuates the push-button switch P.

To stop the motor the switch- M or the switch we may be opened.

I have shown my invention in connection with the control of shunt-woundnon-revere ing motors, but it will be readily understood by thoseskilled in the art that it may also be applied to series orcompound-wound motors either reversing or non-reversing.

The arrangement described in connection with Fig. 1 for preventing theclosure of .to close,

the main switch-S when anyot the starting resistance is cutout. can alsobe applied to magnetic switch controllers by the proper arrangement ofconnections.

I claim- 1. In .a motor control. system, a motor, a switch in the motorcircuit having its operating winding'connected to the motor cirwit, asecond winding on said switch in the motor circuit which causes saidswitch to open when the motor current exceeds a predetermined value.

2. In combination, a switch having a winding which when energized at onevalue prevents the switch from closing and when energized at a lowervalue causes 7 said switch to close, a circuit controlled by saidswitch, and-a winding in said circuit which causes said switch to openwhen the current in said circuit becomes too large.

In combination, a circuit, a switch haviug'contacts in said circuit, awinding on said switch which, energized at one value, will hold saidswitch open, and which, energized at a lower value, will cause saidswitch a second winding onsaid switch which when energized above acertain value causes said first winding to open said switch. 4. Incombination, a main circuit, a main switch having contacts therein, .amaster switch and circuit connections for controlling said main switch,and a winding on said main switch connected to said main circuit whichcauses said switch to open when the current in said main circuit is toolarge.

5. In a circuit controlling system, a circuit, a switch, an operatingwinding therefor, a second winding therefor which when energizenprevents said switch from closing, a thord winding in said circuit whichcauses said switch to open when the current insaid third winding isabove a predetermined value. f

6. In a circuit controlling system, a switch having two windings which,when both are energized, prevent said switch from closing,

means for reducing the current in one wlnding to cause the switchto'close, and a third winding on said switch for causing said switch toopen when thecurrent therein is too large.

7. In a motor control system, amotor, a

switch for closing the motor circuit having two windings which whennormally excited prevent the switch from closing, means for reducing theexcitation of one of said windings to cause said switch to close, athird winding on'said switch connected to the motor circuit which causesthe switch to open when the motor current is above a pre determinedvalue.

8. In a motor control system, a motor, a

switch having a winding connected to the motor circult which causes theswitch to open when the current in the motor circuit becomes too large,said switch having a second winding which when normally energized holds'sjaid switch in itsopen position.

9. In a circuit, a switch having a movable member of magnetic material,means for producing a flux at one end of said member to prevent saidswitch from operating, means for changing said flux to cause said switchto operate, and a winding in said

